A wide range of resources starting with the times tables then introducing the concept of factors, prime numbers, multiples, divisibility tests, LCM and HCF.
Australian Curriculum (NSW) MA2-6NA uses mental and informal written strategies for multiplication and division MA3-4NA orders, reads and represents integers of any size and describes properties of whole numbers MA3-6NA selects and applies appropriate strategies for multiplication and division, and applies the order of operations to calculations involving more than one operation